In the course of its manufacture and/or processing, yarn frequently is advanced substantially continuously from a first location, such as a spinning station, to a second location such as a drawing, twisting and/or winding station. Certain of the yarn manufacturing and processing operations may require that the speed and/or tension of the advancing yarn be at desired magnitudes even when the operations are temporarily interrupted for package doffing, equipment maintenance or other causes. During these interruptions the yarn continuously advanced from the first location must be withdrawn from its normal path of travel and diverted to a waste container or other receiver.
Known devices for withdrawing continuously advancing yarn include so-called suction guns and pneumatic injectors which rely solely upon yarn entraining air streams to withdraw the yarn. Such devices have significant limitations. At yarn speeds greater than about 4,000 meters per minute (65-70 meters per second), their use becomes inefficient and unduly expensive. Additionally, such devices can only convey yarn that is under low tension, and therefore cannot be used to maintain or create tension of substantial magnitude in the yarn. In addition to adversely affecting the quality of the withdrawn yarn, this may create other operational problems. For example, when the yarn is being advanced from a godet roll assembly, failure to maintain sufficient tension in the yarn can easily result in the undesirable formation of laps upon the preceding godet roll or delivery rolls by which yarn is conveyed the to the suction gun or injector.
With the foregoing in mind, a primary object of the present invention is the provision of a yarn withdrawal apparatus and method that operate effectively and efficiently at high yarn speeds and that permit control of the tension of the advancing yarn.
Another object is the provision of an apparatus and method, of the aforesaid type, by which the withdrawn yarn may be discharged in any desired one of a plurality of different directions and in either a substantially straight condition or as a mass or tangle of interconnected windings suitable for use in the formation of a bonded web or the like.